"It was obviously a tough decision. Jason has been in the coaching mix for the past seven or eight years and Steelform Wanganui won the Mead Cup twice when he was assistant to Guy Lennox and once while coach himself - it's an enviable record any coach in New Zealand would be proud of," Cobb said.
Last season Steelform Wanganui went down 29-27 to East Coast after leading 27-3 with just minutes to go.
Cobb confirmed Hoskin's father Dave Hoskin, chairman of the Wanganui union, stood down from the selection process after declaring an interest.
"Dave Hoskin made his interest clear from the start and stood down from the entire process,' Cobb said.
Hoskin junior has already chosen his coaching staff, naming Ruapehu player/coach Daniel Rolls as his assistant and brother Darrell Hoskin as scrum coach. Chris Back will continue as team manager.
Hoskin coached the Marist premier squad for five years, taking the side to a club championship and for the past season was head coach of the Wanganui Collegiate first XV that finished fifth in the North Island secondary schools competition.
"We have all come through the club scene and both Daniel and Darrell have played for Wanganui. The reason I have chosen them is that a new approach is required to take the Wanganui Heartland team to the next level. It was an extremely rigorous selection process and I am looking forward to the challenges ahead. I'm a big believer in Heartland rugby and the public expectation for Steelform Wanganui is very high, as it should be, and we are very aware of that," Hoskin said.
Meanwhile, the announcement has left a bitter taste in the mouth of outgoing coach Caskey.
"To say I'm disappointed is an understatement. I struggle to see the logic given our record. I have personally coached the side to win a Meads Cup and lose one in the last minute, although I was also involved winning two with Guy [Lennox]," Caskey said.
"The most disappointing aspect is the lack of honesty in this selection process. The union tell you one thing, then do another and I can't believe how poorly the Wanganui union is run."